/*
 * Copyright (c) 2002, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package javax.swing.plaf.synth;

import javax.swing.*;
import javax.swing.plaf.*;
import javax.swing.plaf.basic.BasicPanelUI;
import java.awt.*;
import java.beans.*;

/**
 * Provides the Synth L&amp;F UI delegate for
 * {@link javax.swing.JPanel}.
 *
 * @author Steve Wilson
 * @since 1.7
 */
public class SynthPanelUI extends BasicPanelUI
    implements PropertyChangeListener, SynthUI {

  private SynthStyle style;

  /**
   * Creates a new UI object for the given component.
   *
   * @param c component to create UI object for
   * @return the UI object
   */
  public static ComponentUI createUI(JComponent c) {
    return new SynthPanelUI();
  }

  /**
   * {@inheritDoc}
   */
  @Override
  public void installUI(JComponent c) {
    JPanel p = (JPanel) c;

    super.installUI(c);
    installListeners(p);
  }

  /**
   * {@inheritDoc}
   */
  @Override
  public void uninstallUI(JComponent c) {
    JPanel p = (JPanel) c;

    uninstallListeners(p);
    super.uninstallUI(c);
  }

  /**
   * Installs listeners into the panel.
   *
   * @param p the {@code JPanel} object
   */
  protected void installListeners(JPanel p) {
    p.addPropertyChangeListener(this);
  }

  /**
   * Uninstalls listeners from the panel.
   *
   * @param p the {@code JPanel} object
   */
  protected void uninstallListeners(JPanel p) {
    p.removePropertyChangeListener(this);
  }

  /**
   * {@inheritDoc}
   */
  @Override
  protected void installDefaults(JPanel p) {
    updateStyle(p);
  }

  /**
   * {@inheritDoc}
   */
  @Override
  protected void uninstallDefaults(JPanel p) {
    SynthContext context = getContext(p, ENABLED);

    style.uninstallDefaults(context);
    context.dispose();
    style = null;
  }

  private void updateStyle(JPanel c) {
    SynthContext context = getContext(c, ENABLED);
    style = SynthLookAndFeel.updateStyle(context, this);
    context.dispose();
  }

  /**
   * {@inheritDoc}
   */
  @Override
  public SynthContext getContext(JComponent c) {
    return getContext(c, getComponentState(c));
  }

  private SynthContext getContext(JComponent c, int state) {
    return SynthContext.getContext(c, style, state);
  }

  private int getComponentState(JComponent c) {
    return SynthLookAndFeel.getComponentState(c);
  }

  /**
   * Notifies this UI delegate to repaint the specified component.
   * This method paints the component background, then calls
   * the {@link #paint(SynthContext, Graphics)} method.
   *
   * <p>In general, this method does not need to be overridden by subclasses.
   * All Look and Feel rendering code should reside in the {@code paint} method.
   *
   * @param g the {@code Graphics} object used for painting
   * @param c the component being painted
   * @see #paint(SynthContext, Graphics)
   */
  @Override
  public void update(Graphics g, JComponent c) {
    SynthContext context = getContext(c);

    SynthLookAndFeel.update(context, g);
    context.getPainter().paintPanelBackground(context,
        g, 0, 0, c.getWidth(), c.getHeight());
    paint(context, g);
    context.dispose();
  }

  /**
   * Paints the specified component according to the Look and Feel.
   * <p>This method is not used by Synth Look and Feel.
   * Painting is handled by the {@link #paint(SynthContext, Graphics)} method.
   *
   * @param g the {@code Graphics} object used for painting
   * @param c the component being painted
   * @see #paint(SynthContext, Graphics)
   */
  @Override
  public void paint(Graphics g, JComponent c) {
    SynthContext context = getContext(c);

    paint(context, g);
    context.dispose();
  }

  /**
   * Paints the specified component. This implementation does nothing.
   *
   * @param context context for the component being painted
   * @param g the {@code Graphics} object used for painting
   * @see #update(Graphics, JComponent)
   */
  protected void paint(SynthContext context, Graphics g) {
    // do actual painting
  }

  /**
   * {@inheritDoc}
   */
  @Override
  public void paintBorder(SynthContext context, Graphics g, int x,
      int y, int w, int h) {
    context.getPainter().paintPanelBorder(context, g, x, y, w, h);
  }

  /**
   * {@inheritDoc}
   */
  @Override
  public void propertyChange(PropertyChangeEvent pce) {
    if (SynthLookAndFeel.shouldUpdateStyle(pce)) {
      updateStyle((JPanel) pce.getSource());
    }
  }
}
